Using Finite Element simulations to reproduce rotational induced brain injury experiments: Recommendations for the future

The response of the rat brain during rotational acceleration was investigated using finite element simulations to improve understand of the mechanisms responsible for injuries in the brain. Finite element simulations were carried out to match the animal experiment carried out by Davidsson et al (2009). The results from the simulations were compared to injuries inflicted by a rotation of the brain in the animals during the animal experiment. The rat brain was modelled as a viscoelastic, isotropic material; the animal brain model was subjected to a rotational acceleration to mimic the experiments. Different parameters, such as displacement, shear and von mises stress, were investigated and a number of different approaches to model these experiments were investigated. Findings from the simulations show a correlation between shear stress and the location of injuries seen in the animal experiments. The pressure from the simulation was extracted. However, problems were present during the pressure extraction. The solution to this mesh related problem; i.e. changing tetrahedral elements to hexahedral elements, could not be achieved during the given time span of the thesis. Validation methods, i.e. pressure and deformation, were investigated. It was concluded that it will be almost impossible to validate the material stiffness of the brain tissue during the experiment from deformation of the tissue. Since the deformation of the small rat brain will, due to its size, not give a measurable change in displacement for the stiffness tested in the simulations